Magnetic Resonance Imaging and Biochemical markers to assess disability in female subjects with Multiple Sclerosis.

Abstract

Multiple sclerosis (MS) affects the central nervous system (CNS) and is characterized by multiple demyelinating lesions. It is in this context that a need arises for reliable biomarkers such as Magnetic Resonance Imaging (MRI), which could lead to the early diagnosis and therapeutic intervention when maximum potential impact is possible. This study examines the impact of MRI as a marker and the sequences that give the best images to aid in evaluation of disease progression (which can indirectly be seen as disability) and the early diagnosis of MS which will, in turn, lead to more effective management of the disease. METHOD: Sixteen subjects underwent a neurological examination, the Expanded Disability Status Scale (EDSS), blood tests for iron parameters and a 3Tesla Magnetic Resonance Imaging (MRI) scan. In a study of MS, 11 had MRI data that could be analysed by using tract-based spatial statistics (TBSS). Subjects were divided according to the EDSS score (8 of the subjects had an EDSS score of ≤ 3 while 3 subjects had scores of ≥ 6). Diffusion tensor imaging (DTI), the fused Proton Density and Fluid Attenuation Recovery (FLAIR) was utilised to compute the lesion numbers and standard laboratory procedures were used to measure other biochemical markers (serum iron, % transferrin saturation, ferritin, haemoglobin) in subjects with disability and simultaneously assess the disease process. RESULTS: The FA of white matter tracts (WMTs) as a parameter of myelin integrity was lower in subjects with MS only in those who had high EDSS scores. An association between FA and iron parameters, especially percentage transferrin saturation (% Tf) sat were observed, which suggests that iron availability to the WM may be a requirement for optimal myelin functionality. CONCLUSION: The FA of WMTs as a parameter of myelin integrity was lower only in those MS subjects who had high EDSS scores. Subjects who had EDSS scores < 3 (i.e. who had a “benign” disease outcome) had FA values similar to control values and this finding was not related to their age or disease duration. The association found between FA and iron parameters, especially % Tf sat, suggests that iron availability to the WM may be a requirement for optimal myelin functionality. Results also suggest that serum iron concentration, ferritin and % Tf sat had an effect on myelination. The lack of association between FA and Hb suggests that the iron in this protein is not available for WM function.